Limited-rotation unidirectional drive



April 28, 1964 J. R. DAVIS ETAL 3,130,826

LIMITED-ROTATION UNIPIREICTIONAL DRIVE Filed Oct. 12, 1962 John R. Dav/s John E. What/9y United States Patent 3,139,826 LlMiTED-RQTATIGN UNIDHREQTIQNAL DRIVE Eohn R. Davis and John E. Whatiey, Shreveport, La., assignors to United Gas Corporation, a corporation of Delaware Fiied Get. 12, 1962, Ser. No. 259,178 9 Claims. (Cl. 192-12) This invention relates to limited-rotation unidirectional drives which are particularly useful in switches and switching cornmutators of a type useful in recording devices.

The increasing complexity of modern business and industry, particularly in the volume of units, readings, etc., that must be handled, has developed a need for a portable or semi-portable device relatively small in size and simple to operate which is capable of recording information for input into computers. The device may be used for any purpose in which listing of numbers, preparation of tallies, lists or the like is required. For example, the device might be used in stores for taking inventory, in railroads for freight car checking, and the like.

An important aspect of these devices is the need for small, lightweight, and reliable components. It is especially required that such components assure a single entry or recordation for each item of information.

An object of this invention is to provide an improved limited-rotation unidirectional drive.

Another object of this invention is to provide an improved single-rotation latching unidirectional drive.

A further object of this invention is to provide an improved limited-rotation latching unidirectional stepping drive which requires a predetermined minimum advance for each step.

Yet another object of this invention is the provision of an improved stepping drive wherein a predetermined minimum advance is required of each step before another can be started.

A still further object of this invention is the provision of an improved unidirectional commutator drive.

Further objects and advantages of this invention will become apparent from the following description referring to the accompanying drawing, and the features of novelty which characterize this invention will be pointed out with particularity in the claims appended to and forming a part of this specification.

In the drawing:

FIG. 1 is a side elevational view, partly broken away, illustrating an embodiment of the present improved drive in a commutator adapted to be used in a magnetic digital recorder and shown with the latch element in released position;

FIG. 2 is an enlarged fragmentary view of the advance mechanism which cooperates with the latch as shown in FIG. 1;

FIG. 3 is a sectional view, taken along line 33 of FIG. 1, showing details of the knob biasing spring structure;

FIG. 4 is a sectional View, taken along line 4-4 of FIG. 1, showing details of the unidirectional spring clutch drive;

FIG. 5 is a sectional view, taken along line 5-5 of FIG. 1, showing details of the latch mechanism;

FIG. 6 is a fragmentary side elevational view of a part of the drive shown in FIG. 1, partly broken away, illustrating the latch mechanism in its latched position; and

FIG. 7 is a bottom plan view of the knob core member of the drive shown in FIGS. 1, 4, 5, and 6.

Referring to the drawings, an improved latching, limited-rotation, unidirectonal drive embodying the present invention is illustrated applied to a commutator com- "ice prising a single wafer switch 10 of any suitable conventional type. The illustrated structure assures a minimum advance of a complete step or rotation of the commutator before another advance can be begun so as to provide reading connections to all of a plurality of suitable digit switches, whereby all switch entries are recorded by a suitable multiple channel magnetic recording head before a subsequent entry cycle can be started. Details of the magnetic recorder are not disclosed as they do not form part of the present invention. The illustrated commutator with its improved drive can be used with other types of equipment and the improved drive can also be used for other types of unidirectional, limited-rotation, cyclic driving needs.

The illustrated commutator wafer switch 10 comprises stationary contacts 11 mounted on an insulating ring 12 and a central rotatable member 13 drivingly secured to a shaft 14.

This shaft 14 is rotatably supported by a bearing member 15, which extends through an inner mounting plate 16 and is securely fastened thereto by having a shoulder 15' drawn tightly against this plate by a suitable nut 17, which threadedly engages an end of the bearing member 15 and bears against the mounting plate 16. The shaft 14 is axially positioned on the bearing member 15 by a locking ring 18 engaged in a complementary groove in the shaft 14 and is retained in position by the resilient biasing action of a step advance positioning device. This step positioning device comprises a disc 18 fixedly mounted on the shaft 14 for rotation therewith and closely spaced from the underside of a stationary plate 19 fixedly secured to the bearing 15. The outer edges of the disc 18 are formed with a plurality of undulations 20, which may be simply punch pressed in the disc, corresponding in number to the stationary contacts 11 of the wafer switch 19, so that there is a valley 20 of each undulation for each of these contacts 11. The stationary plate 19 is formed with a cylindrical guide 21 radially positioned over the undulations 20 of the disc 18, and may be made in any suitable manner, as by being pressed from the material of the plate to form a slight collar extending upwardly from the plate 19 away from the undulations 20. A resilient stepping arrangement is provided by positioning a suitable ball 22 within the guide 21, which ball has a diameter substantially equal to the internal diameter of the cylindrical guide 21, and resiliently biasing this ball 22 toward the undulations 20 by a suitable spring. This spring may comprise a leaf spring 23 arranged in engagement with the upper surface of the ball 22 and suitably secured to the plate 19. In the illustrated structure, an upset boss 24 formed on the plate 19 secures the spring to the plate and a tongue 23' on the spring extends into a small slot in the bearing 15 further securing these together. In addition, a locating prong 25 may be punched from the plate 19 and extend upwardly through a complementary slot in the edge of the leaf spring 23, so as to locate the spring with reference to the plate 19 and to prevent it from turning around the shaft 14.

In order to assure that the wafer switch rotatable contactor is at all times resiliently biased into engagement with one of the stationary contacts 11, the disc 18 and the rotatable wafer switch member are secured in relation to each other on the shaft 14 so that a valley 20' of the undulations 24) is directly above the contactor of the wafer switch rotatable member. Thus, whenever the shaft 14 is turned, the disc 18 turns with the shaft and the spring 23 biases the ball 22 into a valley 20' of the undulations on the disc and thereby biases the movable switch contactor into engagement with one of the stationary switch contacts 11.

In order to assure the desired sequential engagement of successive stationary contacts 11 by the switch rotatable contactor, the central rotatable member 13 of the switch is adapted to be rotated by a unidirectional drive by manually turning a driving knob member 26. The unidirectional rotation driving connection between the driving knob member 26 and the shaft 14 is provided by a one-way spring clutch comprising a resilient leaf spring pawl 27, which is mounted in a slot 28 formed on a knob driven core member 29 and is securely fastened thereto in any suitable manner, as by a screw 30. This leaf spring 27 is of such a length as to extend beyond the periphery of the knob core member 29 into a counterbore 26" in a cylindrical central cavity 26' in the knob driving member 26, with the free end of the leaf spring 27 adapted to extend into any one of a plurality of circumferentially spaced axially extending grooves 31, FIG. 4, of curved substantially semi-circular cross section formed in the cylindrical surface of the counterbore 26". The length of the spring 27 and its flexibility also are such as to provide for a positive pawl driving engagement of the spring With the sides of a groove 31 when the knob driving member 26 is turned in one direction, clockwise, as viewed in FIG. 4, and to bend slightly so as to slip out of the groove 31 and ride over the cylindrical surface of the counterbore 26" when the knob driving member 26 is turned in the opposite direction. This provides a simple unidirectional drive between the knob driving member 26 and the driven core member 29.

The knob core 29 is fixedly secured to the shaft 14 in any suitable manner, as by a set screw 32 which extends through the core 29 and engages an end of the shaft 14 which extends into a complementary socket 33 in the core 29. The knob driving member cylindrical central cavity 26' provides a sleeve portion adapted to extend snugly rotatably and axially slidably around the core member 29 and provides a cover for all of the enclosed working parts. A leaf spring 34 is inserted between the outer end of the knob core 29 and the inner end of the knob cavity 26', and a screw 35 extends slidingly through an aperture in the end of the core 29, smaller than and coaxial with the socket 33, through an aperture in the spring 34, and is threadedly fastened in the end of the driving knob member 26. The head of the screw 35 loosely slidably fits in the socket 33 in the knob core member 29, and the screw is drawn up, so as to hold the spring 34 under slight compression with the lower edge 36 slightly within a socket 37' formed in a base 37 of the operating knob and slightly above the inner side 38' of a latching recess 38 in the underside of the knob driven core member 29, as is best seen in FIG. 1. In this manner, the spring 34 continuously biases the driving knob member 26 upwardly away from the top of the knob core member, and the head of the screw 35 acts as a stop which limits the outermost position of the knob driving member 26 relative to the knob driven member 29, while the screw holds the two main knob members 26 and 29 in relatively movable assembled relation.

In order further to hold the two main knob members 26 and 29 in relatively movable assembled relation, a retaining pin arrangement may be utilized. This may comprise a retaining pin 39, FIGS. 1 and 4, which extends through the knob driving member 26 along a chord which is tangent to the cylindrical surface of a relief groove 40, FIG. 1, in the side of the knob core member 29. The axial extent of the groove 40 is sufiicient to allow the pin 39 to slide over its inner surface when the knob driving member 26 is depressed, and its upper end in which the pin 39 seats when the knob driving member 26 is biased to its outermost position, FIG. 1, is such that, when the knob driving member 26 is fully depressed, the pin 39 will not be shifted downwardly past the upper edge of the slot 28. This assures complete freedom of opera tion of the slip clutch spring pawl 27 and avoids interference therewith by the retaining pin 39. It is not esd sential that both the screw 35 and the pin 39 be provided, as either will serve to hold the knob members in relatively movable assembled relation.

In order to provide a complete commutated entry or complete cycle of operation of the commutator 10, the rotatable switch member 13 must be turned through a predetermined step, which in this instance is a full turn, for each complete reading or cycle, and each reading or cycle should begin from a fixed position. The knob functions as a driving member for operating the commutator, and the shaft 14 functions as part of the driven member which transmits the step drive to the various commutating and other driven components with which the commutator is used.

Further, in order to provide a starting point for each cycle and a stop indicative of the end of a cycle, a rotation limiting and latching mechanism is provided which is best seen in FIGS. 1, 5, and 6. This mechanism comprises a latch element or detent 41 which is axially movable of the knob and engageable in the recess 38 in the knob core 29 for latching the core member against rotation. The latch detent 41 is pivotally supported in a detent pocket 42 in the knob base 35 by a pivot pin 43 which extends through the detent 41 and is mounted in suitable apertures in the base 35. This detent pocket 42 is located in the base in such a position that when the knob core member is turned so as to place the commutator switch rotatable member 13 in its operating cycle completed position, the latching recess 38 will be positioned directly over the pocket 42, thereby permitting the latch detent to move into latching position in engagement with an end of the recess. A suitable resilient spring 44 is mounted on the base 35 so as to bias the latch detent 41 upwardly axially of the knob into latching engagement with the edge of the recess 38 in the driven core member, as shown in FIG. 6.

The latching mechanism is correlated to the positioning mechanism formed by the disc undulation 2th and the ball 22 such that when the detent 41 is in latching position with the core member recess 38, as seen in FIG. 6, the undulated disc 18 is in a position in which the ball 22 is held by the guide 21 on the leading side of an undulation valley 20, as shown in FIG. 2. The biasing force of the spring 23 on the ball 22 is transmitted to the leading side of the undulation valley and exerts a biasing force thereon which is transmitted by the disc 18 to the shaft 14 in a direction tending to advance the disc and shaft clockwise, as viewed in FIGS. 1, 2, and 6, to bring the undulation valley 2% directly under the guide 21 with the ball 22 at rest in the bottom of the valley 2%). As long as the latch detent 41 remains in latching position in the recess 38, advance of the knob driven core member 29 and, therefore, of the shaft 14 and disc 18 is prevented.

In order to operate the commutator, the knob driving member 26 is depressed so that the lower edge 36 thereof, acting as a release element, presses the latch detent element 41 out of the recess 38. This releases the knob driven core member 29, and the biasing force of the ball 22 on the undulation valley leading side automatically provides a slight relative angular advance of the undulated disc 18 and consequently of the shaft 14 and of the knob driven core member 29 in the driving direction of the knob driving member. This results in an advance of the knob driven member recess 38, so that it is moved out of latching registry with the detent 41. Since the unidirectional clutch drive between the knob driving member 26 and the knob driven member 29 prevents reverse drive of the driven member, and the ball 22 seated in the undulation valley 20' exerts a force tending to prevent reverse rotation of the disc 18 and consequently of the shaft 14 and knob driven member 29, the latching mechanism remains unlatched until the knob drive has been advanced one full turn, whereupon the latch detent 41 reengages the side of the recess 38. This again releasably latches the knob driven member against rotation. In this manner, a very stirnple, reliable, limited rotation, unidirectional drive structure is provided which assures a predetermined advance of a driven member for each operating step prior to actuation for a succeeding step and also assures against reverse rotation of the driven member.

While a particular embodiment of this invention has been illustrated and described, modifications thereof will occur to those skilled in the art. It is to be understood, therefore, that this invention is not to be limited to the particular details disclosed, and it is intended in the appended claims to cover all modifications within the spirit and scope of this invention.

What is claimed is:

l. A latching one-turn unidirectional drive including a driven member and a driving sleeve member mounted rotatable around said driven member, a unidirectional drive means for connecting together said driving and driven members for one-direction drive only, means including a latch element engageable with said driven member for latching said drive, means on said driving member for releasing said latch element, and means operable on release of said latch element for providing an angular advance of said driven member in the direction of said one-direction drive whereby said driven member is displaced relative to said latch element into nonlatching relationship and until said driven member has been advanced one turn by said driving member whereupon said latch element reengages said driven member and again latches it against rotation.

2. A latching one-turn unidirectional drive including a shaft and an operating knob comprising a driven core member connected to said shaft and a driving sleeve member mounted around said core member in rotatable relation thereto, a unidirectional drive means for connecting together said knob members for one-direction drive only, means including a latch element engageable with said driven member for latching said operating knob drive, means on said driving member for releasing said latch element, and means operable on release of said latch element for providing a predetermined relatively slight angular advance of said driven member in the direction of said one-direction drive whereby said driven member is displaced relative to said latch element into nonlatching relationship.

3. A latching one-turn unidirectional drive including a shaft and an operating knob comprising a driven core member connected to said shaft and a driving sleeve member mounted around said core member in rotatable and slidable relation thereto, a unidirectional drive means for connecting together said knob members for one-direction drive only, means including a latch element engageable with said driven member for limiting rotation and for latching said operating knob drive, means on said driving member for engaging and releasing said latch element, means resiliently biasing said driving member out of engagement with said latch element, and means operable on release of said latch element for providing an angular advance of said driven member whereby said latch element and said driven member are moved into nonlatching reiationship and remain unlatched until said knob has been advanced one turn whereupon said latch element reengages said driven member and again latches said operating knob drive against rotation.

4. A one-turn unidirectional drive including a driven member and a driving member rotatably mounted around said driven member, a unidirectional drive means for connecting together said driving and driven members for one-direction drive only, latching means including a recess in said driven member and a latch element engageable in said driven member recess for latching said drive against rotation, means resiliently biasing said latch element toward engagement with said driven member, means on said driving member for engaging said latch element and releasing said latch element from said recess by a predetermined movement of said driving member, and means responsive to release of said latching means for providing a relative angular advance of said driven member relative to said latch element whereby said latch element and said driven member are moved out of latching relationship and remain unlatched until said driven member has been advanced one turn whereupon said latch element becomes reengaged in said driven member recess and again latches said drive against rotation.

5. A one-turn unidirectional drive including an operating knob comprising a driven member and a driving member mounted in limited axially slidable relation to and rotatable around said driven member, a unidirectional drive means for connecting together said knob driven and driving members for one-direction drive only, latching means including a recess in said driven member and a latch element engageable in said driven member recess for latching said operating knob drive against rotation, means resiliently biasing said latch element toward engagement with said driven member, means on said driving member for engaging said latch element and releasing said latch element from said recess by axial movement of said driving member, and means responsive to release of said latching means for providing a relative angular advance of said driven member relative to said latch element whereby said latching means remains unlatched until said knob has been advanced one turn whereupon said latch element becomes reengaged in said driven member recess and again latches said operating knob drive against rotation.

6. A limited-rotation unidirectional drive including a shaft and an operating knob comprising a driven member connected to said shaft and a driving member rotatably mounted around said driven member, a unidirectional drive means for drivingly connecting said driving and driven members, means including an undulated disc se cured to said shaft and a stationary member with a guide therein and a ball slidably mounted in said guide for engagement with undulations in said disc for defining multiple rest positions of said shaft, means resiliently biasing said ball into engagement with said undulations, means for limiting rotation and for latching said operating knob drive comprising a latch detent element and a recess in said knob driven member engageable by said latch detent element for latching said driven member against rotation in a position with said ball on the leading side of an undulation valley, means for resiliently biasing said latch detent element axially of said knob and into said recess, means operable by a predetermined movement of said knob driving member for releasing said latch detent element from said recess and unlatching said knob drive whereby said ball exerts a biasing force on said undulation valley leading side providing a slight relative angular advance of said undulated disc and consequently of said shaft and said knob driven member in said one driving direction so that said latch detent element and said driven member recess are moved out of latching relationship and remain unlatched until said knob has been advanced one turn whereupon said latch detent element reengages said recess and again latches said knob driven member against rotation, and means resiliently biasing said knob driving member out of latch detent element releasing position.

7. A latching one-turn unidirectional drive including a shaft and an operating knob comprising a driven core member connected to said shaft and a driving sleeve member mounted around said core member in rotatably and axially slidable relation thereto, means for drivingly connecting together said knob members for rotation in one direction only, a disc secured to said shaft and having a circle of undulations therearound, means including a stationary member with a guide therein arranged over undulations in said disc and a ball slidably mounted in said guide and engageable with undulations in said disc for defining multiple rest positions of said shaft, means resiliently biasing said ball into engagement with said undulations and thereby providing for angular movement of said shaft and knob core member by angular movement of said disc to bring a valley of said disc undulations under said ball as a rest position, rotation limiting and latching means comprising a latch element and a recess in said knob core member engageable by said latch element for latching said knob core member against rotation in a position with said ball on the leading side of a valley in said undulations, means for resiliently biasing said latch element into latching engagement in said recess, and said knob sleeve member having means for engaging and releasing said latch element from said core recess by axial movement of said sleeve member relative to said core member whereby said ball exerts a biasing force on said undulation valley leading side providing a slight relative angular advance of said undulated disc and consequently of said shaft and said knob core in said one driving direction so that said latching means remains unlatched until said knob has been advanced one turn whereupon said latching means again latches said knob core member against rotation through engagement of said latch element in said core recess.

8. A latching one-turn unidirectional drive including a driven member and a driving member mounted around said driven member in rotatably and axially slidable relation thereto, means for drivingly connecting together said driving and driven members for rotation in one direction only, a disc secured to said driven member and having undulations around the edges thereof, means including a stationary member with a guide therein arranged over undulations in said disc and a ball slidably mounted in said guide and engageable with undulations in said disc for defining multiple rest positions of said driven member, means resiliently biasing said ball into engagement with said undulations and thereby providing for angular movement of said driven member by angular movement of said disc to bring a valley of said disc undulations under said ball as a rest position, rotation limiting and latching means comprising a pivotally mounted detent and a recess in said driven member engageable by said detent for latching said driven member against rotation in a position with said ball on the leading side of a valley in said undulations, means for resiliently biasing said detent into latching engagement in said recess, and said driving member having means for engaging said detent and for moving it out of said recess by axial movement of said driving member relative to said driven member whereby said ball exerts a biasing force on said undulation valley leading side providing a slight relative angular advance of said disc and consequently said driven member in said one driving direction so that said latching means remains unlatched until said driven member has been advanced one turn whereupon said latching means again latches said driven member against rotation through engagement of said detent in said recess.

9. A limited-rotation unidirectional drive including a shaft and an operating knob comprising a driven member connected to said shaft and a driving member rotatably mounted around said driven member, a unidirectional drive means comprising a ratchet notch in one of said knob members and a spring pawl mounted on the other of said knob members and drivingly engageable in said notch on rotation of said driving member in one direction and loosely slidable relative to said one member on rotation of said driving member in the opposite direction, means including an undulated disc secured to said shaft and a stationary member with a guide therein and a ball slidably mounted in said guide for engagement with undulations in said disc for defining multiple rest positions of said shaft, means resiliently biasing said ball into engagement with said undulations and thereby providing for angular movement of said shaft and driven member by angular movement of said disc to bring a valley of said disc undulations under said ball as a rest position, means for limiting rotation and for latching said operating knob drive comprising a latch element and a recess in said knob driven member engageable by said latch element for latching said driven member against rotation in a position with said ball out of a disc undulation valley and on the leading side thereof, means for resiliently biasing said latch element axially of said knob and into said recess, and means operable by a predetermined movement of said knob driving member for releasing said latch element from said recess and unlatching said knob drive whereby said ball exerts a biasing force on said undulation valley leading side providing a slight relative angular advance of said undulated disc and consequently of said shaft and said knob driven member in said one driving direction so that said latch element and said driven member recess are moved out of latching relationship and remain unlatched until said knob has been advanced one turn whereupon said latch element reengages said recess and again latches said knob driven member against rotation.

References Cited in the file of this patent UNITED STATES PATENTS 829,794 Lemp Aug. 28, 1906 1,862,188 Legge June 7, 1932 2,470,186 Price May 17, 1949 2,558,502 Williams June 26, 1951 2,564,872 Wingo Aug. 21, 1951 2,660,904 Hilsinger Dec. 1, 1953 2,840,672 Martin June 24, 1958 2,919,602 Spraragen Jan. -5, 1960 2,935,894 Coronado-Arce May 10, 1960 3,063,299 Kosbab et al. Nov. 13, 1962 3,096,665 Cappelle et al. July 9, 1963 

1. A LATCHING ONE-TURN UNIDIRECTIONAL DRIVE INCLUDING A DRIVEN MEMBER AND A DRIVING SLEEVE MEMBER MOUNTED ROTATABLE AROUND SAID DRIVEN MEMBER, A UNIDIRECTIONAL DRIVE MEANS FOR CONNECTING TOGETHER SAID DRIVING AND DRIVEN MEMBERS FOR ONE-DIRECTION DRIVE ONLY, MEANS INCLUDING A LATCH ELEMENT ENGAGEABLE WITH SAID DRIVEN MEMBER FOR LATCHING SAID DRIVE, MEANS ON SAID DRIVING MEMBER FOR RELEASING SAID LATCH ELEMENT, AND MEANS OPERABLE ON RELEASE OF SAID LATCH ELEMENT FOR PROVIDING AN ANGULAR ADVANCE OF SAID DRIVEN MEMBER IN THE DIRECTION OF SAID ONE-DIRECTION DRIVE WHEREBY SAID DRIVEN MEMBER IS DISPLACED RELATIVE TO SAID LATCH ELEMENT INTO NONLATCHING RELATIONSHIP AND UNTIL SAID DRIVEN MEMBER HAS BEEN ADVANCED ONE TURN BY SAID DRIVING MEMBER WHEREUPON SAID LATCH ELEMENT REENGAGES SAID DRIVEN MEMBER AND AGAIN LATCHES IT AGAINST ROTATION. 